Implantation?

Hi, I had the Mirena removed in October. Since then I’ve been having insane symptoms, mostly symptoms that resemble pregnancy, so I’m probably not actually pregnant but still curious. Each of my periods since removing the IUD has been a couple days late, which isn’t a huge deal but I’ve never had an early or late period in my life, they’ve always been super consistent. Anyways, my Fiancé and I had sex Jan 7th and 10th which both fell in my fertile window. I believe I ovulated Jan 11th but I wasn’t keeping track. In the past week I’ve been constipated every day, I almost threw up when I took a bite of shrimp which is one of my favorite foods and my breasts have been tender, my nipples are bigger than usual and even my fiancé commented on the fact that my breasts look bigger and feel heavier and firmer. The final thing that has me wondering is that I started what I think is my period, 3 days early which again, has never happened. I thought that could be implantation bleeding but it seems too heavy and red for that. I’m not sure what to think, any opinions? If there’s a chance I could be pregnant, can I take a test now or should I wait until I finish bleeding?